Playing games of chance is a popular recreational activity. There are many types of games of chance including table games where players wager against a live dealer such as blackjack, Pai Gow, roulette, Baccarat. Other types of games of chance are offered as automated machines. Examples include slots, poker, bingo, etc. Still other types of games of chance allow players to wager against one another, such as a poker table. In return for a wager, games of chance generate randomly determined outcomes, some of which result in a winning event. Games of chance are often played with wagers having financial value but some games of chance are played with points or other freely available currency having no fiscal worth.
Games of chance may be played in casinos, or at home using electronic devices or mechanical equipment. Gambling via Internet, whether for fun or for money, is also a popular activity.
Games of chance typically associate a winning event with a specific game outcome. For example, achievement of BAR BAR BAR on the payline of a three reel slot machine might pay 20 credits on a 1 credit wager. To increase player interest, bonus awards which are won independently of any single game outcome are sometimes offered. The “mystery” bonus is a popular bonus award that is so named because players cannot easily discern why the award occurred, as it is completely independent of the game's normal schedule of payments.
Mystery bonuses are awarded as a function of game play and are increasingly likely to be won with each game played. FIG. 1a, FIG. 1b, and FIG. 2 are indicative of prior art mystery bonus award operation. Here the mystery award is a progressive amount because it grows in value as a function of each wager made until it is won. Once won, the award is initialized to a starting value and the process begins again. FIG. 1a depicts the initialization procedure which is executed once upon inception of the mystery award and executed again after each winning occurrence of the mystery award.
A mystery progressive award is defined by a starting and ending (maximum) value. The award must be won before the award grows larger than the maximum value. A winning number W is randomly selected from within the range of all numbers between the starting and ending award values. For example, a mystery progressive starts at $1,000.00 and ends at $5,000.00. A winning value W is chosen, at 110 of FIG. 1a, from the range numbers between $1,000.00 and $5,000.00. In this example, W=$2,431.56. The progressive award value is set to the starting value of the award range 120—which is $1,000.00—and the bonus is ready for play as depicted in FIG. 1b. 
The current award value—$1,000.00—is displayed to players 130 and then a new wager is awaited 140. When a wager occurs, the award value is increased as a function of the wager size 150. A commonly used embodiment adds a percentage of each wager amount to AWARD. For example, AWARD=$1,000.00, a wager of $3.00 is made, and FUNCTION is 3% of wager size. AWARD now grows to $1,000.09, as 3% of $3 is 9 cents ($0.09). AWARD is then tested against W at step 160. Since $1,000.09 is less than $2,431.56, the test fails and the flow chart returns to step 130.
This process continues until cumulative play brings AWARD=$2,431.56, making comparison 160 true and the flow chart passes to step 170 where the winner is identified. The winner in this case is the person whose wager caused AWARD to grow equal to W. The winner is then paid the amount won, $2,431.56 at step 180, after which the mystery award is again initialized 190, which simply executes the steps of FIG. 1a again, and the process repeats.
A fixed award mystery bonus works exactly like the progressive mystery bonus award just described, except at step 180, the winner is paid the fixed amount—100 credits for example—instead of the incremented AWARD amount.
FIG. 2 is a prior art four-level progressive mystery bonus display. Enclosure 200 houses the displays and may be configured as an overhead sign, built into the gaming machine, or both. Each display, 210, 220, 230 and 240, represents one progressive mystery bonus award and each grows as a function of wagers made in any gaming machine linked to these awards. Each of the four award values has a winning number W chosen for it during initialization and each award is won independently of the others.
The range for each progressive award 250, 260, 270, and 280 are made known to players so they may understand that, as each progressive award grows, it is more likely to be won.
When one of the mystery awards is won, the winning display immediately begins to alternate every few seconds between the progressive bonus amount won and the winning machine identifier. After the award amount is paid to the winner, either automatically as credits placed on the winning machine or as a manual payment of cash or check directly to the player, the won mystery progressive award is reset to its starting value and again grows as wagers are made in the associated games of chance.
In another embodiment of the prior art, a light or other indicator is placed on, or near each machine in the link. When a win occurs, the winning machine indicator is activated, and remains active, until the award is paid. Because there are so many numbers, multi-level mystery progressives are confusing to many players and this limits their appeal. While the growing award amount, and the corresponding increased likelihood that a win will occur, creates drama and therefore enhances entertainment value to the player, the win occurrence itself is anticlimactic to everyone but the winner because the amount won is known the instant the win occurs.